It is the bedroom scene. Old man Polonius is slain and Hamlet, now wildly unhinged, veers between tenderness - a touch of his mother’s cheek, a look that longs for her affection and absolution - and threat, shaking Gertrude in a violent passion of disgust for bedding his father’s brother. It is an intimate, electric, duet of despair.

Joe West as Hamlet and Chloe Adams as Gertrude, both aged 17, may be slipping their lines a little during this rehearsal, but Roger Harcourt, their director and headteacher, is more than happy at this stunning performance, its depth and complexity made all the more remarkable by the actors’ relative youth. By any measure Hamlet is an ambitious undertaking for a school but Mr Harcourt, now 65, is confident that he has an impressive production ready to go.

Welcome to the 30th Christmas Shakespeare production under Mr Harcourt’s directorship at Freman college, an 800-strong, 13-18 comprehensive in Buntingford, Hertfordshire. But this, in his retiring year, will also be his last. When Hamlet closes for the last night tomorrow in the school’s Arden studio theatre, to an audience packed with past students, the partying will begin as a tribute to an inspiring director.

Mr Harcourt’s passion for the Bard, a passion kindled as a young man when studying literature at Magdalen College, Cambridge, has in some ways driven his headship of the school. Shakespeare’s work, he says, has “the deepest understanding of humanity I know”, an understanding he has spent his working life trying to impart to pupils. His quest has earned him a national reputation.

Rex Gibson, editor of the popular Cambridge School Shakespeare series, which has sold millions of copies, has nothing but praise for the Freman productions. His series is founded on the principle of treating Shakespeare’s work as performance script rather than literary text in an attempt to bring the plays to life for young people, and he has returned to Freman college at Christmas 15 or 16 times to view performances that he says are outstanding among the many hundreds he has seen. “I have seen around 80 productions of Hamlet alone, but I don’t know of another state school where one teacher has for so long produced work of such high quality. I would sooner see a Freman Hamlet than some professional productions.”

There can be few secondary headteachers who teach for as many as 21 periods a week, but Mr Harcourt is determined to know his pupils across the ability range, taking top and bottom sets in English. It is this knowledge that fires his directorship, says Mr Gibson. “Roger is a head who makes it his business to know all the students in his school. He has his director’s cap on right from the time when they first enter, on the look out, wanting to release talent. Every year he finds one or two students who stand out, but as somebody who believes Shakespeare is for all, I am more concerned with the performances he conjures out of students that in other schools wouldn’t have the chance to perform”.

Mr Harcourt, he says, is as meticulous in his attention to minor and non-speaking parts as he is to his main characters. “They are all constantly engaged in the drama of the play; there’s no hanging about or awkwardly looking out at the audience.”

And he meets the language head-on, delivering the words of the Bard in all their fullness. “The Freman approach is a unique undertaking in that apart from some judicious editing, what you get is the whole thing. I am all in favour of adapting the language, using the text as a springboard, but Roger is concerned with students speaking the actual words with meaning.”

Mr Harcourt is concerned to go through every word, of the text, and the rehearsal schedule is gruelling, pupils practising every lunchtime and after-school from the previous June. Every movement, every utterance, is carefully noted and choreographed with no loose ends. At one point, when Daniel Ansell as Barnardo, Ryan Strzelecki as Horatio and Dan Mason as Marcellus are addressing the ghost in the opening scene, Mr Harcourt picks up on some formless shuffling across the stage. “We can’t have these little creepy things. I hate those. Let’s do it again.”

But there is nothing dry or over-bearing about this procedure. The meaning and intention of the text is often hotly debated between himself and his actors and Mr Harcourt seeks the vitality that young people bring to the schedule. Students engaged in horseplay during rehearsals for example, often find their antics being incorporated into stage directions. “Keep it in!” is one of Mr Harcourt’s stock phrases, according to pupils. Students in turn are awestruck by his deep knowledge of the text.

Simon Perkins, 18, who plays the ghost, says Mr Harcourt will often act out their parts to teach by example. ” He often says, ‘Watch me now and listen, I am being you’, then he will come out with your speech word perfect.

Sometimes it seems as if he is the entire works of Shakespeare on legs.”

Certainly, Mr Harcourt is steeped in the language and is keen that his students should be, too. Every year he takes students, ex-students and staff on a summer camp at Stratford-upon-Avon, and every night for a fortnight they see plays and every day they hold seminars, write reviews and compose cod versions of the productions for each other. But he is deeply impressed with the spiritedness of today’s young people, and wants to harness that to bring new life to the plays.

He says: “Over the past 20 years I have seen young people becoming more prepared to take risks with the text. I help to free them up, to give them the confidence to express themselves.”

He is concerned not only to bring out the meaning in the plays, but also to release the nature of the young people themselves. Sometimes his choice of play will be determined by the character of his pupils. He chose Hamlet as his final production partly because he thought Joe West, whom he teaches for A-level English lit, would electrify the role. He says: “Like Hamlet, Joe is very deep and can be fierce and challenging. It’s about getting to the truth inside Joe. The performances are the result of a chemistry between myself, the student and Shakespeare.”

Students present and past greatly appreciate their involvement in the Christmas Shakespeare. With a school structure which means house plays and music, plays and cabarets are taking place throughout the year, they become seasoned performers, but they love getting to know their headteacher in this way. “We inspire him as he inspires us,” says Chloe Adams. Simon Perkins says: “When I started here I thought of Shakespeare as this sort of holy thing on a podium - not for me. But Mr Harcourt helps to demystify the plays. You’re not frightened of them any more.”

Ex-pupil Warren Fitzgerald, now 30, a part-time social worker and professional singer after graduating from Warwick University in drama and English, still goes back to see the Freman Christmas Shakespeare and regularly attends the Stratford summer camp. He will be there with a crowd of old faces tomorrow night. While at Freman he played Orlando in As You Like It, Macbeth in the Scottish play and Malvolio in Twelfth Night. He says Mr Harcourt “knows his students very well, and before he lands something on to you he will have thought about what you can bring to it and how you might handle it. When I left I missed the rehearsals. Staying after school for those was just the coolest thing to do.”

Lizzie Mills is taking a gap year before going on to read English at Clare college, Cambridge. She says: “I never had a free lunch time for the whole of my sixth form at Freman, it was such a big commitment, but it came from Mr Harcourt as well. He helped me to feel comfortable with Shakespeare, not daunted. He took you through the meaning in detail and he was very hot on intonation, on the music of the language. He would drum that into you. At the beginning it feels false and odd to speak in that way, but by the end you are so into your character you feel you are saying these words for yourself.”